Refactor outputs for 0.12, switch from maps to lists

[ludoo]

This is one of the PRs we need for Fabric, that switch outputs in modules supporting multiple resources from maps to list. The rationale is to keep the same order passed in input variables (eg names here) for outputs, which lists do but maps don't as they reorder keys lexically. Having a different order in output vars tripped up ourselves and a few customers in the past.

This also:

• adds outputs for the base google_service_account resources, since it's now possible with Terraform 0.12;
• fixes an issue with formatlist in 0.12 where the resulting list always has a nominal length of 1 and cannot e combined with other list of the same (effective) length, switching to using the new for construct is cleaner and works better.

It's a backwards-incompatible change, so it needs a major version bump. Tests and example have been updated accordingly.

[morgante]

As discussed, let's switch to adding a new output to avoid breaking changes.

[ludoo]

Refactored following yesterday's chat discussion: the map-style outputs are preserved, and new list-style outputs have been added. All tests pass (and they too were refactored to test both styles).

[ludoo]

Re ingwarr's suggestions to switch back to the legacy splat operator, this is the recommended best practice on the Terraform documentation:

We recommend using the full splat syntax for all new configurations since its behavior is generally more intuitive. The older syntax is retained for backwards compatibility but is not recommended.

[ingwarr]

@ludoo Ok, you are right, thank you

[ludoo]

@ludoo Ok, you are right, thank you

I think you need to approve, since you requested changes ;)

[morgante]

Thanks! Just two minor issues - want to confirm you're willing to make this a breaking change.